xrsh-buildroot/buildroot-v86/board/v86/rootfs_overlay/bin/js

#!/bin/sh
PID=$$
test -z "$1" && { echo "Usage: js 'somefunction(1)'"; exit 0; }

source /etc/profile.sh

test -n "$BROWSER" || { alert warning "/dev/browser not active (are you running outside of v86?)"; }
javascript="$*"

# if we are run as shebang, use the file as input
test -f "$1" && {
  javascript="args = String('$*').split(' '); $(cat $1 | tail +2)"
}

# below is not ideal
# first I tried /dev/ttyS* https://github.com/copy/v86/issues/530
# and differentiate processes by prefixing output by PID's 
# to parse it later with AWK, but it was very hairy

OUTPUT=/mnt/run/$PID # com/isoterminal/feat/javascript.js writes output here

touch $OUTPUT
echo -n "PID=$PID; $javascript" > /dev/browser/js
# todo watch file 
sleep 0.1
cat $OUTPUT 
rm $OUTPUT


# should we use flock, an awesome way to make processes read/write the same file
# while preventing 1001 concurrency issues?
# attempt:
#
# flock /dev/browser/js -c "echo \"$javascript\" > /dev/browser/js"